Press platen actuating means



Dec. 27, 1960 H. J. WERNER PRESS PLATEN ACTUATING MEANS 4 Sheets-Sheet 1Filed April 3, 1958 INVENTOR. HERBERT J. WERNER ATTORNEYS Dec. 27, 1960H. J. WERNER 2,966,183

PRESS PLATEN ACTUATING MEANS Filed April 3, 1958 4 Sheets-$heet 2 INV ENTOR.

' HERBERT J.WERNER F155- @@9@ ATTORNEYS Dec. 27, 1960 H. J. WERNER PRESSPLATEN ACTUATING MEANS 4 Sheets-Sheet 3 Filed April 3, 1958 INVENTOR. HERBERT J. WER NEE "HQ T IL ATTORNEYS Dec. 27, 1960 H. J. WERNER 2,965,183

PRES-SPLATENACTUATING MEANS Filed April 3, 1958 4 Sheets-Sheet 4INVENTOR. HERBERT J. WERNER QMQK A1 TORNEY$ United States Patent PRESSPLATEN ACTUATING MEANS Herbert J. Werner, Hamilton, Ohio, assignor toBaldwin- Lima-Hamilton Corporation, Hamilton, Ohio, a corporation ofPennsylvania Filed Apr. 3, 1958, Ser. No. 726,182

3 Claims. (Cl. 144-281) This invention relates to an apparatus forclosing the platens of a steam press or the like when used for themanufacture of sheet material such as chipboard, plywood and the like.

At the present time it is usual to manufacture sheet material such aschipboard or hardboard from properly prepared wood fragments byconsolidating the fragments and a suitable binder under high pressurebetween the heated platens of a press. A large number of sheets areformed at each closing of the press, and for this purpose a large numberof pan-like dies are provided which are filled with the woodfragment-binder mixture and slid into place between movable pressedplatens. As the slide of the press is closed (usually in an upwarddirection) it closes first the lowermost die space, then the second,third, and so on until the platens are in a compact pile with thematerial holding dies therebetween. Continued heat and pressure isapplied to the stack for a predetermined interval of time sufficient tocomplete the proper reaction of the binder material.

In the usual multiple platen press, the speed of closing is made as highas possible to reduce the cycle time and to increase production. If thespeed of closing is made too high the loose Wood fragments are blown outfrom between the platens by the escaping air. Various expedients haveheretofore been proposed to prevent such blowing of the material, butthey have not been entirely satisfactory.

The present invention has for its primary object to provide an improvedmeans to connect the platens of a multiple platen steam press or thelike in such a manner that the overall closure time is very short, yetthe closing movement of any single platen is at a very slow rate so thatthe closure of the press is accomplished rapidly and without blowingmaterial out from between the platens or otherwise disturbing it.

Another object of the invention is to provide improved means forcontrolling the movement of the platens of a multiple platen steam pressor the like which is easy to construct and maintain and which functionsefi'iciently and eifectively to prevent displacement of material frombetween the platens upon closing.

Another object of the invention is to provide a means which willfunction to permit the press to be closed without damage if several ofthe platen spaces have been left unloaded by the operator eitherintentionally or through an oversight.

Other objects and advantages of the invention will become apparent fromthe following description of a preferred form thereof, reference beinghad to the accompanying drawings, in which Figure 1 is a diagrammaticfront elevational view of a press embodying the present invention;

Fig. 2 is a side elevation thereof;

Pig. 3 is a section on line 3-3 of Fig. 2; and

Figs. 4 and 5 are diagrammatic representations of the platen stacks whenclosed, Fig. 4 showing the conditions existing when certain of theplaten spaces have been left vacant and Fig. 5 showing the conditionswhen all of the platen spaces are properly loaded.

The present invention is shown in the drawings as embodied in aconventional steam press the platens of which are hydraulically moved.The pistons and cylinders and the associated control mechanisms areeither diagrammatically disclosed or are completely omitted for the sakeof clarity. The invention comprises, in combination with the pressplatens, means to associate each platen with its neighbor above andbelow in such a manner that a closing movement applied to the lowermostplaten is communicated to all of the platens by linkage mechanismresembling a lazy tong fixed at one end to a movable slide of the pressand at its opposite end to the stationary press crown. The pivot membersfor the lazy tong links are extended to support the press platens. Thus,as the press slide is closed the lazy tong support is closed with theresult that each pivot point and the die or platen supported thereby ismoved in an upward, or the same direction, at varying rates. Forexample, if there are twenty platens supported by the lazy tongmechanism, and a closing motion at the rate of 100 per minute isimparted to the lowermost platen, the platen immediately above it movesupwardly at the rate of 95" per minute, the next succeeding platen atper minute and so on. The actual closing movement then, of each platenagainst the one immediately above it is only 5" per minute. At this veryslow closing rate thus available there is no danger of displacing thewood fragments from between the platens.

In the diagrammatically disclosed press in the drawings, 1t) designatesthe bed of the press and 12 designates the press crown which issupported over the press bed by spaced columns 14 and tied thereto bythe usual corner tie rods 16. In the present instance there are threecolumns 14 at the front and back of the press.

A movable lower slide 18 extends from front to back of the press and issupported for guided movements with respect to the center of the columns14 of the press at both the front and back and is actuated byappropriate power cylinders 19 carried in the bed 10. As is well knownin the art, certain of the power cylinders are used for rapid closing ofthe platens and others for the final pressure applied to the stack ofplatens. In the press shown, outer and larger power cylinders 20 areused to impart a final pressing pressure to the platens through a stool21 which extends from side to side of the press over the slide 18. Thestool may be guided on the outer of the columns if desired. The smallerpower cylinders 19 may be used to move the platens rapidly togetherthrough the mechanism hereinafter described.

Die supporting platens 22 are carried between the stool 21 and the crownof the press and are shown in Figs. 1 and 2 in their open position. Eachof these platens is adapted to receive a pan-like die which is filledoutside 7 links.

the press with an appropriate material such as a mixture of woodfragments and binder. Once the pan-like die has been filled it is placedover one of the platens 22 and the loading is repeated until all of thedie spaces have been filled and the press is then ready for closure.

In the usual construction the platens are supported in their openposition by gap ladders which comprise a spaced pair of staggeredshelf-like stop members which successively engage extensions from eachof the platens as the lower slide is moved away from the crown in anopening movement. Such spacing devices can be dispensed with in the caseof the .present invention or they can be utilized, if desired foradditional supportof the platens in the. open position of the press.

'Fixed to thelower slide 18 is one end of a lazy tong mechanismcomprising pivoted links24 which are attached to a bracket 26 in apivotal connection 28. The links 24 those pivot points which occur atthe centers ofthe Each pivot point includes a pin which extends inwardlytowards the center of the press and is sufliciently heavy that it willeasily support one of the press platens v and the load intended to becarried thereby.

The lazy tong mechanism is, of course, duplicated on the front and backof the press. If the mechanism occupies a substantial length when openit can be supported against movement away from the plane of operationintermediate its ends by one or more brackets 32 fixed to a stationarycolumn of the press. Each bracket comprises wings which extend outwardlyfrom the supporting column sufliciently to encompass the path ofmovement of outwardlyextending pins which are a part of the centralpivot points B between at least two pairs of On the'inner face of eachwing, each bracket is provided with a channel or groove 34 into whichthe pivot pins are extended and since'the movement of these centralpivot points is linear, each channel 34 can extend vertically from topto bottom of the bracket wing. The bracket wings may be relieved atthose points which might interfere with the free movement of. any of theother pivots for the links. a

7 While the projecting pins at. the pivot points A and B may be used tosupport the press platens, additional platens may be supportedintermediate the ends of the 'links and for this purpose inwardlyprojecting pins C are carried by the links of the lazy tong mechanism.Since these pins, and the end pivot points A have a lateral component ofmotion as thepress is closed, the platens supported thereby are providedwith pin receiving grooves 36 formed either in the under surface of theplatens themselves or in wings extending therefrom but which accommodatethe lateral relative movement between the sillpporting pins and theadjacent under surface of the p aten. movement ofrthe platens may beemployed if desired.

In operation, assuming the press to be in the open position shown inFig. 1, the operator loads appropriate dies with the material to beconsolidated and places them from its supporting pins.

Additional guiding means to assure a vertical over the press platens 22..The press closing cylinders are then actuated and the lower slide 18and the'stool 21 begin to rise. At the same time the lazy tong links,

.the lower end of the mechanism being fixed to the slide 18, begin toclose so that each of the platens ad- 'vances towards a retreatingplaten above it except, of -course, for the uppermost one of the serieswhich advances against a die fixed to the stationary crown 12.

number of platens in the series to give the relative closing rate forany one of the platens. The closing rate of each of the platens isequal. Thus, if the rate of closing of the lower slide 18 is per minuteand there are twenty die spaces closed simultaneously, the rate ofclosing of each die space is 5" per minute. Once the platens have beenbrought to the die closing position with the assistance of the lazy tongmechanism, the final pressing of the compound is done by the stool 21and its larger power cylinders 20. Each of the platens is free to leaveits supporting pins during the final pressing operation, there being nofixed pivotal or other connection between these supporting pins and theplatens themselves. At this time stool 21 is free to separate from slide18 so that the final pressure, which is quite high, is not taken by theplaten supporting pins, ,but is transmitted directly from one platen inthe stack to the next. It will thus be seen that the movement of theslide 18 can be very fast without causing any blowing of the materialout from between the platens since the relative movement of each of themwith respect to its neighbor above and below is slow.

The present invention is also of'great advantage in the manufacture ofplywood and other materials where it is necessary to open and close thepress platens repeatedly to allow for the escape of steam that is formedduring the curing cycle. With many of the present presses, and all ofthe commonsuccessively closed stack types, it is necessary to open thepress completely before the last of the die spaces opens. This is a timeconsuming operation that is avoided by the present invention in whichthe die spaces open uniformly as soon as the slide 18 and the stool 21start to descend.

Figure 5 of. the drawings shows the position of the platens 22 when allof the die. spaces between the platens are loaded and under the pressureof the stool 21. In the interests of clarity only a portion of thelength of each platen and die has been shown and the die spaces arerepresented by cross-hatching, In the usual condition of operation allof the die spaces are filled and there is very little movement of any ofthe platens away On occasion, however, the operator either intentionallyor accidentallyniay leave one or more of the die spaces empty so that aplaten would be forced to close directly against its neighbor withoutintervening die or material. No spacers are used between the platens ofthe present press so that the final closing pressure is transmittedroverthe entire area of a platen.

The condition of the platens with unfilled spaces is shown in Fig. 4. Itwill there be seen that the die supporting platens have been carriedupwardly from their engagement with the pivot pins of the lazy tongmechanismby the continued movement of the stool 21. Thus the platenshave been brought to a very closely adjacent position by the movement ofthe lazy tong mechanism and its actuating slide 18 but have beenclosedfinally by the continued movement of the stool 21..

What I claim is:

1. In a multiple platen press mechanism comprising a movable slide, astationary press crown, a plurality of die receiving platens interposedbetweensaidmovable slide and said stationary press crown, meansconnected to saidslide for exerting initial pressure to move the platensinto, contact with, each other, said means mcluding a lazy tong linkagehaving one endfixed to sald slide and its opposite end fixed to saidcrown, means on the lazy tong linkage to support individually saidplurality of said die receiving platens, said supporting meanscomprising projections on said lazy tong linkage extending inwardlyunder said platens but otherwise unconnected thereto, and means to exerta final pressing pressure upon the underside of said platens wherebywhen said platens are moved toward the stationary press crown by saidmeans for;exerting pressure on theunder side of the platens, saidplatens are free to move 01f said supports on said lazy tong linkage.

2. The structure according to claim 1 in which the projections on thelazy tong linkage for supporting the plurality of die receiving platensare positioned at the 5 pivot point between the several link membersmaking up the lazy tong linkage.

3. The structure according to claim 1 in which the supporting means forthe plurality of die receiving platens is intermediate the pivot pointsof the link members 10 making up the lazy tong linkage.

References Cited in the file of this patent UNITED STATES PATENTS LocherDec. 12, 1933 Stanley et a1. Sept. 5, 1939 Perony Apr. 16, 1940 MooreFeb. 19, 1952 Uschmann May 21, 1957 Thurnher Apr. 28, 1959 FOREIGNPATENTS Great Britain Oct. 28, 1936

